Molecular basis of antibody mediated immunity against Ehrlichia chaffeensis involves species-specific linear epitopes in tandem repeat proteins

Jeeba A. Kuriakose, Xiaofeng Zhang, Tian Luo, Jere W. McBride

Research output: Contribution to journalArticle

19 Scopus citations

Abstract

Humoral immune mechanisms are an important component of protective immunity to Ehrlichia species. However, the molecular basis of antibody mediated immunity is not completely defined, and the role of most molecularly characterized major immunoreactive proteins is unknown. In previous studies, we mapped major species-specific continuous epitopes in three surface exposed and secreted tandem repeat proteins (TRP32, TRP47 and TRP120). In this study, we report that protection is provided by antibodies against these molecularly defined TRP epitopes using in vitro and in vivo models. Protection was demonstrated in vitro after prophylactic and therapeutic administration of epitope-specific anti-TRP antibodies, suggesting that the protective mechanisms involve extracellular and intracellular antibody-mediated effects. In vivo passive transfer of individual epitope-specific TRP sera significantly reduced the ehrlichial load and splenomegaly, and protected mice against lethal infection. Moreover, the combination of antibodies to all three TRPs provided enhanced reduction in ehrlichial load similar to that of Ehrlichia chaffeensis immune sera. IgG1 was the predominant antibody isotype in the epitope-specific TRP mouse sera. These results demonstrate that antibodies against linear epitopes in TRP32, TRP47 and TRP120 are protective during E. chaffeensis infection and involves extracellular and intracellular antibody-mediated mechanisms.

Original languageEnglish (US)
Pages (from-to)1054-1063
Number of pages10
JournalMicrobes and Infection
Volume14
Issue number12
DOIs
StatePublished - Oct 1 2012

Keywords

  • Antibody
  • Ehrlichia chaffeensis
  • Epitope
  • Immunoreactive proteins
  • OMP
  • TRP
  • Tandem repeat proteins

ASJC Scopus subject areas

  • Microbiology
  • Immunology
  • Infectious Diseases

Fingerprint Dive into the research topics of 'Molecular basis of antibody mediated immunity against Ehrlichia chaffeensis involves species-specific linear epitopes in tandem repeat proteins'. Together they form a unique fingerprint.

  • Cite this